Exercise device and method

ABSTRACT

An exercise device includes an upper frame supporting a seat back, the seat back enabling support of a torso of a user. A lower seat includes a lower frame that is pivotally mounted to the upper frame. The lower frame includes front and rear support wheels for contact with a supportive surface; and an arcuate member is secured to the upper frame substantially opposite to the seat back. The device also includes a tension arm with a first end movably mounted to the upper frame and a second end movably supported on the supportive surface by a roller or wheel. A tension band is mounted at one end to the tension arm between the first and second ends of the tension arm and at its opposite end to the lower frame by an anchor bar, which is pivotally mounted to the lower frame.

FIELD OF THE INVENTION

The present invention generally relates to exercise equipment. Morespecifically, the present invention relates to light weight systems ofphysical exercise that stress the extensor muscles of the lower body andtrunk.

BACKGROUND OF THE INVENTION

Exercise devices are becoming an increasingly more important part of ourlives. As our society becomes more technologically advanced, we becomemore sedentary. Therefore we must rely on equipment to provide ourmuscles and organs with the stimulation necessary to maintain a healthyexistence. Much of the equipment available is large, inexpensive and notpractical for the average consumer to have in their home. Gyms andhealth clubs are not available to many people, especially in ruralareas. In addition, with our busy lives, many simply do not have time todrive to the gym to exercise and return to home or work. As analternative, home fitness products are inexpensive, lightweight productsthat offer an alternative to the traditional iron. These products mustbe functional, versatile and inexpensive to obtain and maintain.

Weight loss is a key issue with most Americans. As such, a usefulproduct must exercise the larger muscles in the body, specifically theextensor muscles of the hips and legs. These are the most powerfulmuscles in the body and can therefore do the most work. Increased workdone by the body is extra energy expended. Therefore given a constantdietary intake this results in weight loss. In order for this to happen,the product must be used. A product that is too large and bulky, orwhere the user must sit on the ground to use it, is not found to bepopular with the typical consumer. They like to be in a chair-likedevice, off the floor, where they can perform perform the exercises andwhen finished, pick the machine up and roll or carry it away.

SUMMARY OF THE INVENTION

In one aspect, the invention features an exercise device with an upperframe supporting a seat back, the seat back enabling support of at leasta portion of a torso of a user. A lower seat includes a lower frame thatis movably or preferably, pivotally mounted to the upper frame. Thelower frame includes a front support and a rear support for contact witha supportive surface (the floor); and an arcuate member secured to theupper frame substantially opposite to the seat back. When a force isexerted on the seat back toward the arcuate member, the upper frametranslates up and back, rolling on the arcuate member while the frontsupport remains in contact with the supportive surface and the rearsupport is elevated from the supportive surface.

A tension arm may be included that has a first end movably mounted tothe upper frame and a second end movably supported on the supportivesurface. This movable support is preferably by use of a rolling elementsuch as a wheel, bushing roller and a ball bearing. A tension band ispreferably used in conjunction with the tension arm. It is releaseablymounted to the tension arm, optimally between the first and second endsof the tension arm by use of a band receiver, and also to the lowerframe. A spring clip may be used to releaseably secure the tension bandto the tension arm. The tension band may be attached to the lower frameby way of an anchor bar, which is optimally pivotally mounted.

Handles may be mounted to the upper frame adjacent to the lower frame.In addition, a set of upper handles may be mounted to the upper frame, adistal end of said upper handles positioned adjacent the head of a useras they would be positioned on the device. A headrest may be includedthat is adjustably mounted to the upper frame.

An exercise device will optimally include a pair of arcuate membersspaced adjacent to one another and positioned such that there is agreater distance between the arcuate members father away from the upperframe relative to nearer the upper frame. The device may include a platereceiver mounted to the upper frame, thus enabling weight plates to bereceived thereon. This plate receiver is optimally positioned near thelower frame and most importantly positioned on a portion of the devicethat includes vertical movement during an exercise. A cover comprised ofa high friction material is optimally placed on the arcuate members toinsure a high frictional force between the supportive surface and thearcuate member.

In another aspect, the invention includes a method of exercisingincluding providing a device as previously disclosed and seating a useron the lower seat with the back of the user against the seat back. Theuser extends his legs and hip joints, pushing the seat back toward thearcuate member, rolling back on the arcuate member and elevating a lowerportion of the upper frame while extending the body of the user. If atension arm is provided, the method may include displacing the tensionarm and elongating the tension band, thereby increasing work done by theuser.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects of this invention, the various featuresthereof, as well as the invention itself, may be more fully understoodfrom the following description, when read together with the accompanyingdrawings, described:

FIG. 1 is a front isometric view of a body extension exercise machine,the device produced in accordance with the present invention.

FIG. 2 is a rear isometric view of a body extension exercise machine,the device produced in accordance with the present invention.

FIG. 3 is a partially exploded, front isometric view of a body extensionexercise machine with the seat back and lower seats separated, thedevice produced in accordance with the present invention.

FIG. 4 is a side view of a body extension exercise machine shown in astarting position, the user with one hand on a lower handle and theother hand on an upper handle, the device produced in accordance withthe present invention.

FIG. 5 is a side view of a body extension exercise machine shown in afinal or extended position, the user with one hand on a lower handle andthe other hand on an upper handle, the device produced in accordancewith the present invention.

FIG. 6 is a front isometric view of a body extension exercise machineshown in the extended or final position and with the seat backdisplaced, the device produced in accordance with the present invention.

FIG. 7 is a plan view of a body extension exercise machine illustratingthe angled orientation of the arcuate members, the device produced inaccordance with the present invention.

FIG. 8 is a front isometric, exploded view of a body extension exercisemachine shown in its starting position and including two pair of clipsto secure the tension bands, the device produced in accordance with thepresent invention.

FIG. 9 is a front isometric view of a body extension exercise machineshown in its starting position with plate receivers and weight platesadded on one side and exploded on the other side, the device produced inaccordance with the present invention.

FIG. 10 is a front isometric view of a body extension exercise machineshown in its starting position with plate receivers and weight platesadded on both sides and without a tension bar behind the seat, thedevice produced in accordance with the present invention.

For the most part, and as will be apparent when referring to thefigures, when an item is used unchanged in more than one figure, it isidentified by the same alphanumeric reference indicator in all figures.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention is an exercise device that enables a bodyextension movement and is convertible to a flat bench for multipleexercises. The basic version of the device 12 is shown in FIG. 1 in theform of the preferred embodiment of the invention. The device 12includes a seat back 14 and a lower seat 16 for supporting a user in aseated position, similar to a chair. A pair of arcuate members 18 ispositioned behind the seat back 14 to provide for articulating stablesupport when the device 12 is rolled back. In this view only one member18 is seen, and only one member is necessary in order that the device befunctional. For increased stability, a pair of members 18 is optimallyused. This will become more evident further in the disclosure. Therearward movement constitutes the basis for the majority of theexercises that are performed on the device 12. To assist in thismovement, two sets of handles are provided. The first set is the lowerhandles 20 that are mounted to the frame of the device 12 near the backof the lower seat 16. The user, when seated in the device 12, can extendhis arms down, grasp the handles 20 and offer a stabilizing reaction tosliding up and off of the seat back 14 during the extension exercise.The second or upper handles 22 offer an alternative support during thebasic exercise in that the arms of the user are raised and “push” tosecure his body. This alternative positioning of the body stresses thedeltoid muscles and triceps rather than the biceps and forearms whenusing the lower handles 20. Subtle variations such as this offer a keyversatility to the capabilities and therefore the success of theproduct. The upper handles 22 have another function in that the device12 can be fully extended back on the arcuate members 1o creating abench. The upper handles 22 are then positioned to provide stability toallow abdominal exercises to be performed. Arcuate members 18 each haveone end connected to upper frame 30 via transverse stub extensions (notnumbered) and effectively form extensions of the lower ends of upperhandles 22. The upper ends of the arcuate members 18 can also attach tothe frame substantially orthogonal to the lower ends of the upperhandles 22. The opposite ends of arcuate member 18 are connected tolower frame member 34 or handles 20.

Another key element in this version of the invention is also shown here.A tension arm 24 is movably mounted to the device 12 behind the seatback 14. This arm 24 is supported by a support 26, preferably in theform of a wheel or roller as shown here. The support 26 is supported onthe floor on which the device 12 sits and translates away from the seatback 14 as the device 12 rolls back on the arcuate members 18. When thishappens the tension bands 28 elongate, thus work is done. Differenttension bands 28 can be used for varying the resistance. For example,the different tension bands 28 can be made thicker, of differentmaterials, etc.

In FIG. 2 the device 12 is shown from the rear, thereby illustrating thestructural elements in this the preferred embodiment. An upper frame 30provides the structural support for the seat back 14, the arcuatemembers 18, lower handles 20, upper handles 22 and a first end of thetension arm 24. The tension arm 24 is pivotally mounted to the upperframe 30 by way of a clevis 32. The second key frame element is thelower frame 34. The lower frame 34 provides a secure mounting surfacefor the lower seat 16 and provides a base mount for the tension bands28. Optimally, two tension bands 28 are used, as is shown here, that aremounted between the tension arm 24 and the lower frame 34. In thisposition, the device 12 is at “rest” and therefore the tension bands 28are not extended significantly beyond their resting length. At thesecond end of the tension arm 24, two supports 26 are provided. Aspreviously noted, these are intended to move or translate along thefloor or other supportive surface. Here, two supports 26 are used. Thisis not necessary for the function of the device 12 in that a singlesupport 26 or roller could be used. Two supports 26 are used to offergreater stability to the arm 24 and the device 12 when in use.

Another aspect of the invention illustrated here is an adjustableheadrest 36. The headrest 36 is comprised of a head pad 38 and a malepost 40. The male post 40 is telescopically received by the upper frame30 and secured in a desired position by placement of a pin in one of thetube holes 42, which is received in a corresponding one of a pluralityof spaced apart holes (not shown) in male post 40. Additional holes 44are used to secure the seat back 14 to the upper frame 30. Theversatility of the movable headrest 36 is another advantage to moreadequately fit a variety of physical types of users.

Another view of this embodiment is shown in FIG. 3. Here the seat back14 and lower seat 16 have been separated to show the structure of thedevice 12. Of specific interest in this view is the lower frame 34. Thelower frame 34 is pivotally mounted to the upper frame 30. When in thisposition the bottom portions of the arcuate members 18 are in contactwith the floor as well as the supports 26. In this, the startingposition of the exercise, the lower seat 16 must substantially supportthe body weight of the user. This load is transferred to the lower frame34, which must be supported by the floor on which the device 12 sits.For that, the lower frame 34 must also have supports. The upper frame 30is supported from behind by the arcuate members 18. The upper frame 30is pivotally mounted to the lower frame 34, which includes frontsupports 46. Without a rear support 48, the area of pivotal connectionof the upper frame 30 and the lower frame 34 would hit the floor. As theexercise is performed, with the weight of the user on the device 12, theinitial movement of this pivotal connection area would drag on the flooruntil enough vertical displacement was achieved. By rolling back on thearcuate members 18, the lower frame must be horizontally displaced.Because of that, the preferred embodiment of the front supports 46 andthe rear support 48 are wheels or rollers. A slider or pad with a lowcoefficient of friction could be used, but a rolling element ispreferred. This eliminates any damage to the floor by the device 12scratching along the initial movement of the exercise.

The tension bands 28 are mounted between the tension arm 24 and thelower frame 34. The lower frame 34 acts as an anchor to provide areaction force to the tension applied by the tension bands 28 when theyare stretched due to the displacement of the tension arm 24 when in anextended (rolled back) position. To aid in the alignment of the tensionbands 28 with minimal axial slippage and associated wear, an anchor bar50 is provided. The anchor bar 50 is pivotally mounted to the lowerframe 34 and therefore acts as an extension of the lower frame 34. Theanchor bar includes a band receiver 52 in the form of a rod that acceptsthe end of the band 28. The anchor bar 50 is shown here to be pivotallymounted to the lower frame 34 at the axis of the wheel, which is therear support 48. This is a design choice and considered to be thepreferred embodiment, but that precise location of the mounting of theanchor bar 50 to the lower frame 34 is not considered critical to theinvention. The ability of the anchor bar 50 to move or pivot relative tothe lower frame 34 is of value in that as the device 12 is extendedbackward, the positions of the tension bar 24 relative to the lowerframe 34 and relative to the upper frame 30 both change. The rotationaldisplacement of the lower frame 34 relative to the band 28 can be great.When the band 28 is under tension this load produces a great deal offriction on the band receiver 52. The band 28 is traditionally a moldedrubber bar, with holes to receive the band receiver 52. This is not agood bearing surface. A better bearing can be provided in the pivotalattachment of the anchor bar 50 to the lower frame 34, thus reducingwear on the band 28, increasing its functional life and reducing itslikelihood to inadvertently come off during the exercise session. Alsoregarding safety, a cover 53 comprised of a high friction material isoptimally placed on the arcuate members 18 to insure a high frictionalforce between the supportive surface and the arcuate member. Thisreduces the likelihood of the device 12 slipping when used and makes itreduce noise and potential damage to the floor.

The starting position of the device 12 is shown in FIG. 4, from the sidewith a user 54 positioned on the device 12. The user 54 is seated on thelower seat 16 and for illustration sake is shown grasping a lower handle20 with his left hand and an upper handle 22 with his right hand. Theuser 54 has his back positioned against the seat back 14 and his feet 56on the floor in front of the device 12.

The final position is shown in FIG. 5 where the user 54 has extended hisleg 58 and hip joints, pushing against the floor, with the feet 56relatively stationary, pushing the seat back 14 back on the arcuatemembers 18. This results in rolling the device 12 back on the arcuatemembers 18 raising the rear support 48 of the lower frame 34 off thefloor. At this degree of rearward extension, the user 54 may be raisedoff the lower seat 16. The front support 46 maintains contact with thefloor in that it is pivotally mounted to the upper frame 30. This allowsthe user to fully extend his hips and legs without being physicallyinhibited by any aspect of the device 12. If the device 12 were extendedfurther, depending upon the subtleties of the pivotal connection of thelower frame 34 to the upper frame 30, a limit of the angulardisplacement can be built in. In this case the front support 46 wouldeventually be raised off the floor. This provides more work done by theuser in that this seat 16 structure has weight and is being verticallydisplaced. As long as the lower seat 16 and the seat back 14 can becomesubstantially coplanar, there is little potential for the lower seat 16to interfere with the movement of the legs 58 of the user 54 andtherefore can reach a range limiting stop relative to the seat back 14.The angular displacement of the tension arm 24 is also illustrated here.In FIG. 4 the angle between the upper frame 30 and the tension arm 24 isnoted by the angle α. When extended, as in FIG. 5, the new angle α₁ isvisibly greater than the acute angle α. This angular displacementresults in an increased length of the tension bands 28 between these twofigures. The tension band 28 is a tension producing spring that whenelongated applies a force that opposes this elongation. Thus, work isdone by the user to elongate the tension bands 28. The user pushingagainst the seat back 14, stabilized by the lower handle 20, pushing onthe upper handle 22 or any combination thereof, does this work.

The device 12 is shown in the elongated or extended position in FIG. 6with the seat back 14 displaced to better view the elongated bands 28and the function of the anchor bar 50. As the tension arm 24 isdisplaced rearward and the device 12 rolls onto the arcuate members 18,the angle between the lower seat 16 and the tension band 28 changesdramatically. The angular displacement of the tension band 28 relativeto the lower seat 16 is roughly twice that of the angular displacementof the band 28 relative to the tension arm 24. The tension band 28 is anelastic element, as previously note and preferably made of a natural orsynthetic rubber material. These materials typically have a highcoefficient of friction with smooth steel. The band receivers 52 aretypically smooth steel. Therefore, continuous rotation under tension cancreate a great deal of wear. The applicants have overcome this issue byusing an anchor bar 50 that is pivotally mounted to the lower frame 34.This moving anchor bar 50 enables virtually no angular rotation of theband 28 on the band receiver 52 of the anchor bar 50, which acts as apart of the lower frame 34. This greatly increases the life of the bands28 when used on the device 12.

Shipping size is another issue to home fitness products. In many casesit is desirable for the product to ship in a “knocked down” staterequiring some assembly by the user. The value of the knock downproducts as to the shipping costs is greatly reduced, which can bepassed on to the consumer as a lower sale price. In doing this, it isdesirable to design the components so that they take up a minimal amountof carton size without compromising the function of the product.

Stability of the device while in use is always an issue of concern. Thebase must be wide enough to allow for normal side-to-side forces withouttipping the device over. This is ever apparent when getting on to orexiting the device. The applicants addressed this issue in several ways.A top or plan view of the device 12 is shown in FIG. 7. Here the lowerseat 16 is quite apparent in this view along with the upper handles 22and the lower handles 20. The tension bar 24 extends from the back ofthe device 12 with the tension bands 28 in place as previouslydisclosed. Two unique features are apparent in this view. First, thearcuate members 18 are cantered or flared to the outside. This is doneto increase the width of the contact points of the arcuate members 18with the floor while maintaining a minimal sized frame structure tosupport the members 18.

The second feature is the width of the supports 26 on the tension bar24. These supports 26 are purposefully positioned to add to thestability of the device, both in a starting position (as when enteringand exiting the device 12) and in an extended position as when beingused. This support width also aids in stability in case only one of thetension bands 28 would be used. The eccentric load on the frame memberswould be decreased by the increased width of the supports 26 on thefloor.

A partially exploded view of the device 12 is shown in FIG. 8. Thisbetter illustrates the knock down capability of the device 12. It is notnecessary that the consumer assembles all components, and in most casesit is preferable not to do so. This does give the manufacturer theassembly options. In addition, this view illustrates one example of themanufacturability of this device 12. The elements are as previouslydisclosed, with the exception of two sets of clips 60. These clips 60can take a variety of physical forms but have been determined by theapplicant to preferably be a form of a torsion spring. The clips 60 canbe provided in pairs, as shown here and connected by a tether 62. Thiscan connect an upper to a lower clip 60, as shown here, or a right to aleft clip 60. The tether 62 is not critical to the function of thedevice 12, but only added as prevention against losing the clips 60. Thefunction of the clips 60 is to be received by the band receivers 52 onthe outside of the bands 28. The clips 60 apply a frictional force tothe band receiver 52 to releaseably secure the band 28 on the bandreceivers 52. This prevents the inadvertent dislodging of a band 28.This could be especially detrimental when the device 12 is extended andthe bands 28 are under tension.

An alternative to the preferred embodiment is shown in FIG. 9. In thisembodiment, the lower portion of the upper frame, or the bases of thehandles 20 are fitted with plate receivers 64. The plate receivers 64enable receiving weight plates 66. These plates 66 are shown here in twodifferent sizes, or weights. The amount and combination would becompletely up to the user and the structural capability of the weighteddevice 68. The weight plates 66 are shown to be in position on thedevice 68 on the rear side and exploded on the far side. The purpose ofthe weights 66 is to provide additional weight for additional resistanceduring the exercise. As was illustrated in FIG. 5, this lower portion ofthe upper frame is elevated during the extension exercise. Therefore,adding additional weight would increase the work done by the user, andtherefore the load on the muscles of the user. The tension bands 28 onthe tension arm 24 can still be used in this embodiment of theinvention.

A second alternative to the preferred embodiment is shown in FIG. 10. Aspreviously disclosed, the presence of the weight plates 66 on the platereceivers 64 provides additional resistance to the muscles of the userperforming the exercise. In light of that, it is possible to add enoughresistance though weight plates 66 to substitute for the previouslydisclosed tension arm 24 and tension bands 28. This embodimentillustrates this version of the device 70 without the tension producingelements of the tension arm 24 and tension bands 28. The generalfunction of the device 70 would be identical to that as previouslydisclosed only with the noted parts being absent.

1. An exercise device comprising: an upper frame; a lower frame movablymounted to the upper frame and including a front support and a rearsupport adapted to contact a supportive surface; a seat back secured tothe upper frame; a lower seat secured to the lower frame; and an arcuatemember mounted to said upper frame substantially opposite to said seatback to permit rolling of said exercise device on said arcuate memberwhen a force is exerted on said seat back in a direction toward saidarcuate member, whereupon said rear support is elevated from thesupportive surface.
 2. An exercise device as in claim 1, furthercomprising a tension arm with a first end movably mounted to said upperframe and a second end adapted to be movably supported on saidsupportive surface.
 3. An exercise device as in claim 2, wherein saidsecond end is adapted to be movably supported on the supportive surfaceby use of a rolling element.
 4. An exercise device as in claim 3,wherein said rolling element includes a roller selected from the groupconsisting of a wheel, a bushing roller and a ball bearing.
 5. Anexercise device as in claim 2, further comprising a tension bandreleaseably mounted between said tension arm and said lower frame.
 6. Anexercise device as in claim 5, further comprising an anchor barpivotally mounted to said lower frame, for mounting said tension band tosaid lower frame.
 7. An exercise device as in claim 6, wherein saidanchor bar includes a band receiver adapted to receive one end of saidtension band.
 8. An exercise device as in claim 5, wherein said tensionband is releaseably mounted to said tension arm at a position betweensaid first end and said second end of said tension arm.
 9. An exercisedevice as in claim 5, further comprising a band receiver for mountingsaid tension band to said tension arm.
 10. An exercise device as inclaim 5, further comprising a spring clip used to releaseably securesaid tension band to said tension arm.
 11. An exercise device as inclaim 1, further comprising a set of lower handles mounted to said upperframe adjacent to said lower frame.
 12. An exercise device as in claim1, further comprising a set of upper handles mounted to said upperframe, distal ends of said upper handles positioned adjacent the head ofthe user positioned on the device.
 13. An exercise device as in claim 1,further comprising a headrest adjustably mounted to said upper frame.14. An exercise device as in claim 1, wherein said arcuate memberincludes a pair of arcuate members spaced adjacent to one another andpositioned such that there is a greater distance between the arcuatemembers farther away from said upper frame relative to nearer said upperframe.
 15. An exercise device as in claim 1, further comprising a platereceiver mounted to said upper frame for enabling weight plates to bereceived thereon.
 16. An exercise device as in claim 1, furthercomprising a plate receiver mounted on said device and positioned nearsaid lower frame.
 17. An exercise device as in claim 1, furthercomprising a plate receiver positioned on a portion of said device thatvertically moves during an exercise.
 18. An exercise device as in claim1, further comprising a cover on a portion of said arcuate member, forproviding a high friction contact between the supportive surface andsaid arcuate member.
 19. An exercise device comprising: an upper framesupporting a seat back, the seat back enabling support of at least aportion of a torso of a user; a lower frame supporting a lower seat, thelower frame being pivotally mounted to said upper frame and including afront support and a rear support adapted to contact a supportivesurface; and an arcuate member secured to said upper frame substantiallyopposite to said seat back to permit rolling of said exercise device onsaid arcuate member when a force is exerted on said seat back in adirection toward said arcuate member, whereupon said front supportremains in contact with the supportive surface.
 20. An exercise deviceas in claim 19, further comprising a tension arm with a first endmovably mounted to said upper frame and a second end adapted to bemovably supported on said supportive surface.
 21. An exercise device asin claim 20, wherein said second end is adapted to be movably supportedon the supportive surface by use of a rolling element.
 22. An exercisedevice as in claim 20, further comprising a tension band releaseablymounted between said tension arm and said lower frame.
 23. An exercisedevice as in claim 22, further comprising an anchor bar pivotallymounted to said lower frame, for mounting said tension band to saidlower frame.
 24. An exercise device as in claim 23, wherein said anchorbar includes a band receiver adapted to receive one end of said tensionband.
 25. An exercise device as in claim 22, further comprising a bandreceiver for mounting said tension band to said tension arm at aposition between said first end and said second end of said tension arm.26. An exercise device as in claim 22, further comprising a spring clipused to releaseably secure said tension band to said tension arm.
 27. Anexercise device as in claim 19, further comprising a set of lowerhandles mounted to said upper frame adjacent to said lower frame.
 28. Anexercise device as in claim 19, further comprising a set of upperhandles mounted to said upper frame, distal ends of said upper handlespositioned adjacent the head of the user positioned on the device. 29.An exercise device as in claim 19, further comprising a headrestadjustably mounted to said upper frame.
 30. An exercise device as inclaim 19, wherein said arcuate member includes a pair of arcuate membersspaced adjacent to one another and positioned such that there is agreater distance between the arcuate members farther away from saidupper frame relative to nearer said upper frame.
 31. An exercise deviceas in claim 19, further comprising a plate receiver mounted to saidupper frame for enabling weight plates to be received thereon.
 32. Anexercise device as in claim 19, further comprising a plate receivermounted on said device and positioned near said lower frame.
 33. Anexercise device as in claim 19, further comprising a plate receiverpositioned on a portion of said device that vertically moves during anexercise.
 34. An exercise device as in claim 19, further comprising acover on a portion of said arcuate member, for providing a high frictioncontact between the supportive surface and said arcuate member.
 35. Foruse with an exercise device including an upper frame and a lower framemovably mounted to one another, the upper frame having a seat backsecured thereto, and the lower frame having a lower seat securedthereto, the lower frame including a front support and a rear supportadapted to contact a supportive surface; and an arcuate member mountedto said upper frame substantially opposite to said seat back, anexercise method comprising the steps of: seating a user on said lowerseat with the back of the user against the seat back; extending the legsand hip joints of the user, thereby pushing said seat back in adirection toward said arcuate member; and rolling back on said arcuatemember and elevating a lower portion of said upper frame while extendingthe body of the user.
 36. A method as in claim 35, wherein said devicefurther includes a tension arm with a first end movably mounted to saidupper frame and a second end movably supported on said supportivesurface and a tension band releaseably mounted between said tension armand said lower frame, said method further including the step of:displacing said tension arm and elongating said tension band, therebyincreasing work done by the user.